There are conventional techniques for analyzing the skin condition based on a captured image of the skin so as to visualize and quantify the analysis results. For this, it is necessary to extract objects to be analyzed that are present on the skin surface based on the skin image.
Patent Document No. 1 discloses a technique for extracting skin texture and/or wrinkles from an obtained skin image by performing image processes, including a cross binarization process and/or a short-line segment matching process.
Patent Document No. 2 discloses a technique for extracting skin grooves by converting the brightness values of pixels so that the variance in brightness value of the captured image is greater than or equal to a predetermined value, binarizing each pixel, and performing a matching operation between binarized black pixels and predetermined short-line segments.
Non-Patent Document No. 1 discloses a technique for extracting wrinkles by predetermining the edge direction of the skin based on local features, and performing a filtering process using a Gabor filter having a predetermined orientation.